1. Field of the Invention
The present invention relates to athletic shoe soles and, more particularly, to a dynamic sole that includes hydraulic pistons for cushioning the alternating weighting and unweighting of the shoe by the wearer.
2. Description of the Prior Art
There are several shoe soles that include trapped air pockets which cushion the weighting and unweighting of the shoe during the wearer's walking or running. The sizes of the air pockets can vary from those which include air bubbles of minuscule size as occur naturally in foam, plastic, or rubber to large capsules which can also be formed in foam materials during their creation by the choice of ingredients. Even larger cavities can be created by molds or the deletion of center portions in multilayered materials. The prior art of athletic shoes further includes soles that contain compartments with variable or fixed internal pressures which can be pumped up with pressurized air or gas from internal or external pumps.